Telegraph system.



MLJ. CARPENTER.

TELEGRAPH SYSTEM.

APPLIUATION FILED APR. 19, 1910.

1,007,527, Patented 0013.31, 1911;

MYRON J. CARPENTER, OF LA GRANGE, ILLINOIS.

TELEGRAPH SYSTEM.

Specification of Letters Patent.

Patented Oct. 31, 1911.

Application filed April 19, 1910. Serial No. 556,408.

To all whom it may concern:

Be it known that I, MYRON J. CARPENTER, a citizen of the United States, residing at La Grange, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Telegraph Systems, of which the following is a specification.

My invention relates to improvements in telegraph systems and has for one of its objects to provide a telegraph system to be used in conjunction with telephone line circuits, whereby the signals afforded by the electrical impulses, constituting the dots and dashes of the Morse alphabet, transmitted by the said system, may be easily-read and understood in the telephone receiver.

Another object of my invention is to provide in a system of the character'described, a means whereby signals may be sent over the wire conducting a telephone service without disturbing the conversation, or without interrupting the service in any respect.

Another object of my invention is to provide in the same local apparatus, a means for carrying on telegraphic communications, or telephonic communications, or both, simultaneously without interference, one with the other.

Other and further objects of my invention will become apparent to persons skilled in the art from a consideration of the description hereinafter contained, taken in conjunction with the drawings, wherein- Figure 1 is a schematic diagram of the connections, showing my system of telegraphy asinstalled on-a telephonic circuit; Fig. 2 is a plan view of a part of the apparatus used; Fig. 3 is a section taken on line 33 of Fig. 2, showing a telegraph-key adapted for use in carrying out my invention; and Fig. 4: is a section of a detail taken on line 44 of Fig. 2.

In all of the views, similar reference characters indicate similar parts.

Should the primary circuit of a telephone set be opened and closed, as with an ordinary telegraph key, and an effort made thereby to transmit telegraphic signals, the receiving operator will get what is called a back stroke. This is due to the fact that the sound made by the diaphragm of the telephone receiver in opening the telegraph key is louder than the sound that is made when said circuit is closed by the key,

thus creating a confusion that is unintelligible to the expert telegrapher.

WVhen the primary circuit of a telephone system is opened, the kick of the coil, or discharge of the primary circuit, produces a louder and more distinct sound in the telephone receiver located in the secondary circuit than when said primary circuit is closed.

In telegraphy, the dominant sound, to render the characters intelligible to the receiving operator, must be made when the key is depressed, and hence when the key is located in the primary circuit of a telephone system and the circuit is opened when it is depressed it produces a sound in the telephone receiver corresponding to that produced when the circuit is closed in the ordinary system of telegraphy.

I have found in practice that if the contact point of a telegraph key be reversed, that is to say, upon the downstroke or depression of the key the primary circuit of the telephone system is opened, and on the upstroke ofthe key said circuit is closed, that impulses may thus be created on the primary circuit which will be intelligible and readily understood by telegraph operators when heard at the receiving station by a telephone receiver at a remote distance from the point of transmission. This special form of telegraph key cooperates with the telephone receiver and intermediate primary and secondary circuits to produce a new and useful result in the telephone receiver that has not heretofore been accomplished. In my system of telegraphy, therefore, I use a telegraph key wherein a circuit is opened when the front end of the key is depressed, and closed when the front end of the key is released; this being just the reverse of the operation of an ordinary telegraph key.

In the manipulation of my key, the dots and dashes are made by the operator as in the ordinary key used, in the regular telegraphing systems. The transmitting operator need not be aware of the change of character of the key, the respective dots and dashes being transmitted thereby in a telephone system with as great fidelity and clearness of understanding When received by the telephone receiver as wh dots and dashes are transmitted in a telegraph circuit and received in the ordinary sounder.

' ing post 9 by wire In carrying my system into effect, I have suggested a self-contained instrument which may be bridged in a telephone'system at any place in the telephone circuit. The instrument may also be employed for the transmission of speech as in the ordinary telephone set, or it may be employed for the sole purpose of transmitting telegraphic signals over the telephone circuit, when the signals will be readily understood by an operator using a telephone receiver at any point on the telephone circuit.

My self-contained instrument is especially adapted for railroad purposes and may be used for confirming parts or all of a telephonic communication. It frequently happens in telephonic conversation that certain words as spoken by mouth, which are difficult of enunciation, are not always clearly understood. Such words and figures may be confirmed by the use of the telegraph attachment, and for this use alone my device is especially advantageous.

In Fig. 2, 5 indicates generally a telegraph key of suitable character, and 6 indicates generally an induction coil, including a primary, having terminals, 7 and 7, and a secondary having terminals 8 and 8. A battery, 10, and a transmitter, 11, both of the ordinary type, may be connected to the local circuit binding posts, 9 and 9 and thereby included in series with the primary of the induction coil. The telephone receiver is to be connected to the terminals, 8 and 8, and a line circuit is to be connect ed to the terminals, 12 and 12. By this arrangement, the secondary circuit, including the secondary winding of the induction coil and the telephone receiver are connected in series, and are then directly connected to the line as in ordinary telephone practice.

In the diagrammatic illustration, Fig. 1, wire 13 is connected to main 14c, and to the secondary coil, 8 and thence by wire, 15, to the telephone receiver, 16, and thence by wire, 17, to the terminal, 8, and by wire 18, to one of the main lines, 14, thus completing the secondary circuit of the device.

The primary circuit is as follows: Start-- ing at the battery, 10, the battery is connected to the terminal 9 by wire 19, and thence to the primary windings of the induction coil to the wire 20, to one terminal of the telegraph key by wire 21, thence to the hind- 22, and thence by wire 23 to the transmitter 11 and thence by wire 2% to the battery, thus completing the primary circuit.

Referring to Fig. 3, which is a cross sectional View through the telegraph key, it will be observed that the anvil contact, 25, which is the cooperating contact of contact 26, of the lever bar, 27, by which the circuit is usually closed by the ordinary telegraph key, is insulated, and is not in circuit at any time being solely and only for the purpose of a limit stop. The contact 27 is secured to the end of the screw, 28, and is adjustable thereby, the screw, 28, being held in adjusted position by means of the check nut, 29. An insulated contact 30 cooperates with the contact, 27, to close the circuit when the telegraph key is released, or upon its upstroke. The usual adjusting spring, 31, is employed for yieldingly maintaining the lever 27 in its raised position. The spring 31 is adjustable in the usual manner by means of the screw, 32, and the check nut, 33, fixes the screw in adjusted position. The switch closing lever, 34, is insulatedly supported on the base, 35, by means of the insulated terminal screw, 36, and to this terminal one of the circuit wires is connected as shown in Fig. 2. The wire 22 is connected to the frame 35 of the key, and therefore, a yielding tongue, 37, secured to the upright, 38, is a means by which with the switch lever 34, the primary circuit of the device is closed.

The circuit is opened when the switch lever 34 is pulled toward the key lever, 27, an effect the reverse of that of an ordinary telegraph key. In order to transmit telegraphic signals on a telephone circuit, it is necessary to push the switch lever, 3 1, until it makes contact with the yielding tongue, 37, and the primary circuit of the device will be thereby closed, and upon the manipulation of the key the circuit may be opened and closed between the contacts 27 and 30, to produce the desired dots and dashes of the Morse characters. The circuit being opened when the button 39 of the key is depressed, and closed again when the spring 31 operates to raise the lever 37 until the contacts 27 and 30 are again brought together.

In the practice of my invention, the signals sent over the line are clear and distinct, are not harsh and unpleasant to the ear, and may be translated over the circuit and received by a telegraph operator without interference with the ordinary conversation that may be taking place between two other stations and other parties at the same time.

WVhile I have herein described in some detail a particular embodiment of my invention, it will be apparent that other embodiments may be efiected with changes in the details and arrangement thereof without departure from the invention as defined by the following claims.

What I claim is:

1. In a system of telegraphy, a secondary electric circuit containing a telephone recelver, a primary electric circuit containing a telegraph key, said circuits being in inductive correlation and said key being arranged to open the primary circuit on its down stroke and to close said circuit on its up stroke, whereby the greatest disturbance of said telephone receiver, caused by the circuitopening efiect of said down-str0ke, constitutes the most audible indication of dots and dashes for the telegraph message.

2. In a system of telegraphy, a line circuit common to a plurality of telephone sets each set provided with a circuit containing a telephone receiver, another circuit in inductive relation thereto containing a telegraph key arranged to open the latter circuit on its down stroke and to close it upon its upstr0ke, whereby the effect produced by the down-stroke of said key forms the most audible indication for the dots and dashes of the telegraph characters.

3. In a system of telegraphy, a circuit containing a telephone receiver, a circuit in inductive relation thereto including a telegraph key, said key adapted and arranged by opening said circuit to produce an efiect in the receiver circuit upon its down-stroke translatable in the receiver into a sound dominating that produced upon the circuitclosing upstroke of the key.

In testimony whereof I hereunto set my hand in the presence of two witnesses.

MYRON J. CARPENTER.

In the presence of- MARY F. ALLEN, W. LINN ALLEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

